Contents

# mkl_?csrmv

Computes matrix - vector product of a sparse matrix stored in the CSR format (deprecated).

## Syntax

Include Files
• mkl.h
Description
This routine is deprecated. Use mkl_sparse_?_mvfrom the
Intel® oneAPI Math Kernel Library
The
mkl_?csrmv
routine performs a matrix-vector operation defined as
`y := alpha*A*x + beta*y`
or
`y := alpha*AT*x + beta*y,`
where:
alpha
and
beta
are scalars,
x
and
y
are vectors,
A
is an
m
-by-
k
sparse matrix in the CSR format,
A
T
is the transpose of
A
.
This routine supports a CSR format both with one-based indexing and zero-based indexing.
Input Parameters
transa
Specifies the operation.
If
transa
=
'N'
or
'n'
, then
y
:=
alpha
*
A
*
x
+
beta
*
y
If
transa
=
'T'
or
't'
or
'C'
or
'c'
, then
y
:=
alpha
*
A
T
*
x
+
beta
*
y
,
m
Number of rows of the matrix
A
.
k
Number of columns of the matrix
A
.
alpha
Specifies the scalar
alpha
.
matdescra
Array of six elements, specifies properties of the matrix used for operation. Only first four array elements are used, their possible values are given in
Table “Possible Values of the Parameter
matdescra
(
descra
)”
. Possible combinations of element values of this parameter are given in
Table “Possible Combinations of Element Values of the Parameter
matdescra
.
val
Array containing non-zero elements of the matrix
A
.
Its length is
pntre
[m-1] -
pntrb

.
Refer to
values
array description in CSR Format for more details.
indx
For one-based indexing, array containing the column indices plus one for each non-zero element of the matrix
A
. For zero-based indexing, array containing the column indices for each non-zero element of the matrix
A
.
Its length is equal to length of the
val
array.
Refer to
columns
array description in CSR Format for more details.
pntrb
Array of length
m
.
This array contains row indices, such that
pntrb
[
i
] -
pntrb

is the first index of row
i
in the arrays
val
and
indx
.
Refer to
pointerb
array description in CSR Format for more details.
pntre
Array of length
m
.
This array contains row indices, such that
pntre
[
i
] -
pntrb
-1
is the last index of row
i
in the arrays
val
and
indx
.
Refer to
pointerE
array description in CSR Format for more details.
x
Array, size at least
k
if
transa
=
'N'
or
'n'
and at least
m
otherwise. On entry, the array
x
must contain the vector
x
.
beta
Specifies the scalar
beta
.
y
Array, size at least
m
if
transa
=
'N'
or
'n'
and at least
k
otherwise. On entry, the array
y
must contain the vector
y
.
Output Parameters
y
Overwritten by the updated vector
y
.

#### Product and Performance Information

1

Performance varies by use, configuration and other factors. Learn more at www.Intel.com/PerformanceIndex.